Phenyl vinylene carbonate

Ferrini and Marxer65 have recently shown that vinylene carbonate reacts with primary amides, in the presence of polyphosphoric acid, to yield 2-substituted oxazole derivatives. Yields are low (2-34%), and phenoxy- and phenyl-acetamide, p-methylbenzamide, and salicylamide do not give oxazole derivatives. Although the reaction has been interpreted according to Scheme 3, the nucleophilic attack of a nitrile molecule (from the amide dehydration), with a nitrilium salt as intermediate (Scheme 4), cannot be excluded.06... 

The ability of furan to undergo both the forward and reverse Diels-Alder reaction has been used to synthesize 1,3-dioxoles, and the reaction appears to have wide applicability. In Scheme 42 the synthesis of 2-phenyl-l,3-dioxole is shown. The key to the process is the dialcohol (119), which is obtained from vinylene carbonate as shown. The dialcohol (119) has the potential of serving as an intermediate for a variety of 2-substituted 1,3-dioxolanes (73JA7161). 

Both diastereomeric aziridines (47), upon heating with vinylene carbonate, furnished four readily separable diastereomeric pyrrolidine esters which were transformed into both enantiomers of 1,4-dideoxy-l,4-iminoxylitol and l,4-dideoxy-l,4-iminoribitol <92TA68l>. 3-Phenyl and 3-unsubstituted 2-alkenoyl-methylaziridines synthesized via Grignard reaction from the corresponding cyano-aziridines have been thermally transformed into ring-fused pyrrolidine compounds via azomethine ylide intermediates <85JOC4ii4>. 

Disubstituted ethylenes, RCH=CHR, are only polymerized to high-molar-mass products under certain conditions. For example, vinylene carbonate (I) polymerizes free radically to high-molar-mass products, whereas maleic anhydride (II) only yields low-molar-mass compounds under these conditions. 1,2-Diphenyl ethylene cannot be polymerized to poly(phenyl methylene) (III), but phenyl diazomethane, C6H5CHN2, can be. 

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